New research that identifies growth opportunities for salmon aquaculture in Tasmania has found that suitable locations for potential industry expansion would be in offshore waters along our south east and north coasts.
Researchers have finalised the Statewide Salmon Aquaculture Spatial Planning Exercise, which is a collaboration between IMAS, the University of Tasmania and the Department of Natural Resources and Environment Tasmania (NRE Tas)
Lead author Dr Myriam Lacharité said the report serves as a spatial planning decision-support tool to help government better understand potential growth opportunities of salmon aquaculture in Tasmanian waters.
“The project involved a biophysical suitability assessment of State waters across Tasmania, generally extending to three nautical miles offshore, and a social, economic and environmental evaluation in key areas to evaluate their viability to host salmon aquaculture operations,” she said.
“When considering biophysical suitability alongside other marine uses and ecological values, the report found most opportunities for salmon aquaculture generally reside in deeper offshore waters off Tasmania’s coast.
“This is because the biophysical suitability for salmon aquaculture was high in offshore environments, pending available infrastructure and cost-effective operations, and fewer conflicts with other marine users and ecological values were identified in these areas.”
Biophysical suitability includes ocean characteristics, such as water temperature and wave height, as well as factors restricting salmon aquaculture in Tasmania, such as the presence of rocky reefs. Our biophysical suitability assessment excluded the east coast between Tasman Island and Cape Portland, existing Marine Farming Development Plan areas and waters less than 10 metres.
“The biophysical suitability assessment alone found that environments on the south east coast, from Tasman Island to South East Cape, and the north coast, west of Cape Portland including the Furneaux Group and King Island, were generally suitable areas for salmon aquaculture,” Dr Lacharité said.
“We then combined these results with key social, economic and environmental information in these two coastal regions. These includes marine uses and activities, like fishing, boating, coastal access, coastal development and residences, areas of high navigation and marine infrastructure, as well as conservation and ecological values.
“Four hypothetical scenarios were used to assess these factors to understand whether conflicts and potential trade-offs around shared marine resources may arise between salmon aquaculture and other marine users.”
Dr Lacharité said following these assessments, a few key locations were deemed suitable for salmon aquaculture.
“In the south east, cold water temperature and deep waters, especially offshore, indicated high biophysical suitability. However, due to wave height increasing further offshore in this region, biophysical suitability is relatively greater closer to shore, with better conditions found in waters in the north of Storm Bay.
“On the north coast, suitability is impacted by relatively higher water temperatures and shallower depths than in the south east, but a calmer ocean environment indicated high biophysical suitability. The most optimum waters are offshore off the coast of the Furneaux Group, as well as between Penguin and Three Hummock Island.”
Associate Professor Jeff Ross, who leads the IMAS Aquaculture Environment Program, said that the project is an important step towards better understanding the potential for sustainable salmon aquaculture expansion in Tasmania.
“However, this research doesn’t eliminate the need for any future salmon aquaculture expansion applications to continue following the Tasmanian marine planning process underpinned by the Marine Farming Planning Act 1995,” he said.
This statewide assessment refined an approach previously developed as part of the Pilot Marine Spatial Assessment Tool study in the D’Entrecasteaux Channel in 2020.
For more information on the planning process, visit the NRE Tas website.
Published 21 January 2022